Hi,
I want to rebuild the engine of my MT2. When I got it a year ago, I used some loctite on the four screws holding the engine. Now, I cannot remove them

I read on the website of loctite, I should use heat. So I held a candle under the screw for a few seconds, but the screw still doesn't move and the head starts to strip. Does anyone have tip on how to remove those screws?
Thx,
Nick