[Mike N]

Rap it firmly with a small hammer.
Edit, saw you did that.

Get a bigger hammer.

 

[Mike N]

That made me laugh because I just had my vehicle in the garage and my mechanic was banging hard on something, trying to get it free, when he suddenly dropped the hammer, reached for a torch, and said exactly what that meme says at the bottom!
A few seconds later and the part was free.

Good luck!

Two most popular mechanics tools in the salt belt are a BFH and a torch.