Any one ever replace caps or modify there Xovers

There probably are dozens of us who have replaced x-over parts; I've done it to maybe a dozen speakers.

General advice is to replace lo-quality parts with hi-quality ones, but that advice is as useless as your question is general. Get to the x-overs, trace schematics, etc. Then we can help.

And we'd need a budget, too, as there's little sense to recommend you buy $300 of parts if you've have more like $100 in mind. BTW, $100 might be a good budget for the tweeter caps. My tweeter filters have about a grand worth of Teflon-film caps in them, but no one ever called me sensible. :-)

UH? Can't you just LOOK at it and draw the Sketch-o-matic?
The DCR for the inductor can be measured.....amp off and lift one leg.
The problem would be the inductor value. That, too, can be measured.

Start tracing wires.....and maybe take a few photos.

Might be a dumb question..but is the schematic absolutely necessary? Couldn't you just replace the old 10 uF cap with a better 10 uF cap and not have any issues?

I am with Magfan and Fishboat. It is worth trying if you really like your speakers, they'll never be Nautilus though.