I had the same problem when I installed mine, I striped both screws very badly, the superglue trick didn't work, I bought some precision screw extractor from iFixit but the metal used for the screws was so soft that it only stripped them more.
After about a month of trying different stuff, I ended up drilling them out. The trick to avoid damage to your computer is to only break the head of the screws, than lift the bracket and take out the remaining part with pliers. Took me about 2 mins lol should've done it from the beginning. The 2nd screw (far right, near the cables) is harder to take out with pliers, you'll have to remove 2-3 others screws and little pieces in order to have enough room to work around it.
The only problem is that you'll have to find new screws to replace them.