How are new valve guides fitted, do you need an engineer to do it with a press, or are they screwed in. Anybody got info.

Their for sale on ebay for £10 a set x8 + the same for inlet, does anybody know who can do these in the Midlands (south Staffs) the car runs fine except smokes on tick over at traffic lights, and when stopped, gotta be the soluation fit new guides, every thing else ok, uses loads of oil.

1.6 sxi 2000 model X16 XEL engine

Thanks for any help.