I have the special tool to replace the rear subframe bushes with the subframe in situ........did mine in less than a day , you're welcome to borrow it if you cover all postage/courrier charges
Some years ago a motor trader mate of mine sold a Porsche to a well spoken /dressed gentleman who paid with a bankers draft........which turned out to be a forgery..... he lost the Porsche and the money
Try selecting all gears with the engine NOT running ......if all gears can be selected with normal effort , try again with engine running ......if the problem is there with engine running its a clutch problem ......probably hydraulics hths