An EASA CPL/MEIR cannot be converted to a TCCA equivalent however your training and command experience should for the most part be creditable toward the Canadian experience requirements.
You can review these requirements for the CPL(A) at
421.30(4)(a) in the Canadian Aviation Standards. The CPL theory course is not mandatory if these experience requirements are met in full (see 421.30(9)). When counting the PIC time be aware that TC may interpret your operating capacity during JAA/EASA skill tests and proficiency checks as training time rather than as PICUS. The logging rules are otherwise generally very similar and can be found in the
AIM (LRA).
For the MEP see
421.38(3), and for the IR refer to
421.46. If you want to do PIC flying in Canada before obtaining the CPL then you might want to pick up a foreign licence validation certificate (see
421.07). You can generally obtain the FLVC from TC in person by presenting your EASA licence & medical certificate, logbook, photo ID, and CAD$45.
Obtain a Category 1 medical certificate as soon as possible because it can take several weeks to receive, and you must have it before sitting any written exams (see
421.13(1)). You do not need a recommendation letter to attempt the written tests (421.13(3)(d)) because you hold an ICAO Annex 1 compliant licence/rating at an equivalent, or higher, level. Be aware of the time minimum waiting periods between resits (14 days in the case of a second attempt). Once completed, you can do any desired refresher flying training before attempting the flight tests. You do not need a Canadian pilot licence/permit/certificate to attempt these, and you do not need a recommendation letter (421.14(3)(d)), however you will need to complete a short test for the ROC-A (radio permit). If you're an EU citizen then you won't need a student visa for a study period shorter than 6 months.
It can take up to 90 days for TC to process the application and, because you're relying on foreign experience, no temporary privileges for the CPL will be granted immediately after a successful flight test. You may wish to make a (sworn) copy of your logbook for TC. You'll also need to submit a photograph because Canadian licences come in the form of an Aviation Document Booklet which resembles a passport. Any TC licensing officer can sign the back of the photo. See ADB guidelines in
AC No. 400-001.
You'll find a comprehensive list of regulations you're supposed to know in the study guides published by TC [1] and a set of condensed notes that you might find helpful are at ref [2] below. Warwick Green [3] has authored numerous exam prep guides. Harv's Air does a reasonably good online ground school for the CPL/IR [4]. Harv's also has a webpage on this process [5].
Finally, whenever you wish to renew your EASA MEP/MEIR, you'll find the derogations in
2014/69/EU and
2014/425/EU useful.
[1] Transport Canada's
Study and Reference Guides.
[2] Langley Flying School's
online classroom.
[3] Warwick Green's exam prep guides,
Sharper Edge Solutions.
[4] Harv's Air:
online ground school.
[5] Harv's Air:
Foreign pilot licence conversion.