How do I disconnect the ABS wiring plug from the unit.

[Dub Style 0]

Ever since i fitted my mk4 rear calipers my brakes are utter shite, there is very low effort on the rear wheels. I wanted to temporarily disconnect the abs to see if its nothing to do with that............cant get the damn plug off the unit......help.....

[dr_mat 0]

Just pop the bonnet, find one of the connecting plugs at the top of the suspension towers and disconnect it there. That will throw an ABS sensor fault and it'll disable the ABS - bingo.

It's more likely that you need to fiddle about with the rear brake bias valve. The back brakes are only supposed to up to about a third of the braking effort at ANY time, so you are much more likely to notice changes to the front brakes than the rears (though since presumably you have new pads they'll take a little while to bed in). More likely is you need to re-bleed the rears and this is what's causing the problems.