Bypass deck's amp with RCA?

I'm thinking of wiring in an 8 track player into my system... just cuz I can. Right now I have an RCA-based EQ that runs to my amps and speakers. I want to run the 8 track through the EQ, but all of the players I've found are too old to have RCA's, just post-amp speaker wires. Does anyone know how easy/hard it would be to rewire some preamp RCA outs to a deck? Or does anyone have any other idea of how I might want to wire it? Thanks.

Rewiring the preamp in any deck is largely impossible because of the use of integrated circuits... so if I was you I'd just use simple line-out converters (speaker-to-line level convrters) and there you have it.

Find the volume control on the deck - wire your RCA to the potentiometer "wiper" and that should give you what you're looking for.