How to remove epoxy glue from driver board

Hello guys

How to remove this kind of epoxy glue from driver board !? Any ideas without doing any damage to the driver board ?

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Chlorinated solvents used to be recommended to soften epoxy but I haven't had much luck. Scrubbing with solvents can work. Those aren't likely to cause damage.

Heating and picking it away often works but can do damage when you don't know precisely what and where the underlying components are.

I've also used a dremel with an abrasive wheel but you have to be careful.

Those rarely fail. Are you sure that they're defective.
 
I have sawtooth wave at the gate pads on the output mosfets for the first 3-5seconds when i turn on the amplifier. Then the protection circuit kicks in and amp goes into protect.
No matter if i plug in RCAs with sinewave or not, the same.

I also suspect 2SC4672 + 2SA1797, they get warm but read fine on the MM.
Q11 + Q7 also read fine on the MM, but i know they often fail. I've even tested the last two on the transistor tester - they've showed HFE~40.

The IC's which are glued if i'm being correct are lm211 + tl072c