Yep - Marvin's guide has it covered.
Gently heat up the insert from under the playfield and "tap" the insert out. If possible, try it on an old playfield if you have one lying around.
$#$thanks for that strange ,I didnt know about the heating up bit ,its weird because its not a couple of inserts, its all of the inserts. I suppose i try it with hair dryer as i havnt got a heat gun 
Hair dryer will be fine - take your time. Practice and experiment with the hair dryer - Just like the character in your avatar 
*%*I only started working on the 4square last week ,& she reset straight away ,which was a good sign.the playfield aint to bad either (apart from inserts) I then went silly cleaning points &+ of course other things started stuffing up!
