So I've been trying to take my headlights apart to retrofit them multiple times now but cant seem to get them open!

I've set the oven at 265, put them in for 6-8 minute intervals then tried prying all around the lens.

I have repeated this probably 20 times now and still no luck.

Any tips?

 

Put them in there for a longer period of time... 10-13 Minutes...

 

X2

More time will help, but ease your way up in time. Heating only enough to get them apart.