You will have to retest for your driver's licence here in BC as there isn't a reciprocal agreement with the UK. There is the "written" Knowledge test and then the actual driving exam. Upon successful completion of both tests, you will be issued a BC driver's licence, as well as have your British DL returned to you.
If there are any questions you have, I'll certainly try and help out.
You may also want to peruse the following link about getting insurance in BC and having your claims discount recognized in order to save some coin. ICBC, the provincially run vehicle insurance corporation, requests that prior claims history be presented in a certain way, otherwise it won't be accepted. It's difficult to get many of the insurance companies in the UK to detail your history in a policy point form, but hopefully you'll be able to get them to do so! There is a letter (application form) on the link that can be sent to your insurance company for them to complete. If you have difficulties getting the letter in the correct format, bring along the policy papers you received each time you renewed your insurance. That will help in determining your claims status here.