I have to digitize 23.000 slides, any tips?

My grandpa was a very ambitious hobby / semi professional photographer and this is his legacy. This is just one of several shelves.

I'm open for any input, tips and ideas!

I think I'll get a used used dslr or mirrorless only for this purpose since I don't feel like putting this much usage on my current DSLR and I'd like to have it in RAW format.