Injector wiring

Been having a look at the wiring for these and it all looks a bit tired,brittle sleeving and some exposed wires near at the connectors.How much of a job is it to replace the wiring, and whilst I'm at it refurb/clean/UPGRADE the injectors
Put new Magnicors on today but left the plugs as they're only 4k old.I'm finding that the more I improve the thing the more I look at the little niggles

A proper injector clean wouldnt do any harm, there's years worth of crap in there. Don't bother upgrading on standard management. As PeterG found, slightly bigger injectors, thus more fuel lost him about 30bhp on the rollers...