Unclejockie

Hi, Newbie on site. My X reg XJ8 has developed a clatter on start up & idle which would appear to be due to a known fault with Timing Chain Tensioner(s). I've been quoted funny money to get it fixed. The car is otherwise minted & I'm reluctant to let it die. Is there an idiot's guide, or an experienced owner to help with a fix? I'm assuming you can go in from the front rather than hoiking the engine out.