You are welcome H-D!
I am going to throw a curved ball at you here. You can fly in EASA land on an EASA issued Validation of your foreign licence for limited period of time, but there are restrictions of course. You never really get anything for free in aviation!
An EASA 1st class medical, a bunch of correctly completed paperwork including sending (or taking) all your log books to the Aviation Authority in the country in which you wish to fly, and a paid fee of course may/should get you a 12 month Validation of your ICAO CPL(H) or ATPL(H).
Once the Validation is issued, you may fly commercially in EASA land until the expiry date of that Validation, but you may only fly commercial Aerial Work (read utility) and you may not fly passengers (apart from employees of the company for whom you fly - they are not considered to be passengers!)
Before your initial Validation expires, and only if you are enrolled on an approved theoretical knowledge course at an EASA Approved Training Organisation, and can prove that you really are working towards converting your ICAO licence to EASA and not just trying to get a freebie ride in EASA land for a few more months, your Validation may be extended a further once only and for a further limited time; the length of which is at the mercy of the Aviation Authority in that country. Expect 3 - 6 months, buy a lottery ticket if you get 12.
By the expiry date of that extension, EASA firmly believes you will have had sufficient time to convert your licence, and a further extension will not be entertained. You may claim that extreme circumstances have prevailed and that you wish to contest the length of extension afforded to you; this can be done citing point 2, Annex III, A. Commission Regulation (EU) No 1178/2011 which states that "...the extension shall cover the period of time necessary for the licence to be issued in accordance with Part-FCL", however, it seems that each Authority within EASA has an "interpretation of the rule" card they sometimes like to play, so good luck with that!
The ICAO to EASA conversion is lengthy, of that there is no doubt. However, a lot can be done to prepare for the conversion before hand. There's nothing stopping you from buying the conversion course books, getting your head into them in a big way, doing all the hard yards in your spare time waiting at a rig, or when it's a down day for weather, then nipping over to EASA land for a 3 week holiday and doing the 2 week long consolidation courses back to back if it can be arranged, then sitting all 13/14 exams in one go during the last week of your holiday!
From there, you'll know which exams you've passed and can forget, and can concentrate on the ones you blew for your next trip over. You never know, you might pass them all first time, it's been done plenty of times before - maybe not in one sitting though..!
Out of interest, you can now sit UK based EASA Theoretical Knowledge E-Exams at Jerez in Spain, Orlando in the US, and Sepang in Malaysia. Other countries may follow in due course, contact the UK CAA for more information.
From there, once you have all 13/14 exams passed, you can knock the flight training and skill test out in 2 weeks easily. All the small piston engined aircraft are available in the UK, plus 206s, 350s, 355s, 109s, and maybe 500s. 135s are in country for training of course, but I don't think they are currently available for commercial skill tests as they have to be operated by the CPL(H) ATO, and on their books for CPL(H) training and examination!
BTW, the training organisation will respect and treat you as a CPL/ATPL, just not a licenced one in their country. Their mission is to polish you to be able to pass the EASA skill test under the guideline "training as required". Expect 4 - 7 hours unless you are already a qualified CFI/TRI/TRE/FX on type in the local area!
The oral part of the skill test examination is fairly non existent so to speak, there is no major quizzing like in other countries, however the examiner can ask you any question pertaining to the preparation of your pre-flight paperwork, the weather, etc, and of course the skill test flight itself.
For the skill test, the navigation section is 3 parted and 1/2 the skill test battle, the rest is general handling, both emergency and non-emergency.
Start honing your skills on using a map again, including how to unfold and refold it whilst flying as a GPS is not allowed during the test (apart from the diversion part of the nav-ex.) If there is no GPS physically installed and hard mounted in the aircraft in which you take the test, tough, an auxiliary GPS is not allowed!
Hope that helps a little more.
Fly Safe!