You'll have to do flight training at the discretion of the FTO you convert with (usually around 5 hours i think) and it has to be in a complex aircraft ( I dont think complex is required in Canada for CPL).
The big bit is youll have to do all the groundschool here. Most people do the ATPLs and they can take anything from 7-8 months fulltime!! You can do CPL exams but there is not much point because if you have any aspirations towards the airlines then you will need ATPLs and the CPLs cant be upgraded.
Look in Lasors on the CAA website for details.
www.caa.co.uk
Good luck.
Foz