I think the computer tech textbook should definitely be recycled. For the Greek Lexicon, maybe you could contact a local classics department and see if one of their students would have a use for it? Or just leave it in one of their lounges.

If you install an appropriate version of Linux with a nice GUI, using it day-to-day is not very different from Windows -- the hard part is actually getting it installed properly and making sure it works with all your peripherals. If you're willing to pay someone to install Linux on your machine (and maybe answer occasional questions later on if you run into issues) I'd expect making the switch to be pretty straightforward. That said I'm not sure how easy it is to find people to do that sort of thing. (My sister is very good at helping little old ladies with tech stuff, and has done it for pay for people she knew through her UU church in the past, but she's not local to you and I don't know if she's currently doing this side hustle anyway.)

(I am planning to install Linux on this laptop as a dual-boot for the same reasons. But (a) I have enough tech-savvy that I'm not too intimidated and (b) I live with A, who has installed Linux on many computers.)