Nasty matted fur :/

So my new(er) bun Oscar was rescued about two months ago. I got him when he was super sick, and he's just feeling better now. When I rescued him, he was covered in mats. I did my best to brush out/cut out the easy to reach ones, but since he's been sicky, I haven't wanted to really bother him.
Well just now i've tried to get at the really nasty mats and they're just awful. They are all over his upper tummy and his front legs. I've done my best but I really don't feel comfortable getting with scissors that close to the skin.
Any tips?
Or should I just wait until I take him in to the vets to be neutered and have them trim/shave him when he's under?
Thanks

Just realized this was in the wrong section *shakes head* Oh where is my mind today. Sorry loves

I'd get him shaved at the vets poor love xx

I would get him shaved and let his fur have a fresh start. Worked wonders with my persian cat that I took in.

When I had Maxi he was so badly matted and coated with poo the vet nurses very kindly gave him a good shave using the trimmers they have there that cuts fur close to the skin but not buns with a good wash afterwards.
Maxi was a cuddle bun who let them do so and looked a lot happier afterwards.
If you have a very stressed bun you may need the vet to do so under sedation but chat to the vet about what would be best for the lad.