To get your JAR CPL, you need to first of all sit the CPL ground exams....these are similar to the current ATPL exams but apparantly not as difficult (I did the ATPL's so I can not confirm that this is true!!). I do believe that you can do a corespondance course for these papers, so you can keep your job!!!!
For the flying training (ab-initio) you have to do 25 hours dual instruction to obtain a Form170a. This is to prove that you are up to standards before test. This is done by the FTO that you choose!
I am unsure how much you will have to do as you already have a few flying hours....suggest that you phone the CAA-FCL.
Hope that is some help to you.
MM