If we're talking like for like and they are both non "immobiliser pumps type pumps" then dead easy, can do it without the proper kit as well using a few drill bits, from memory about 8mm to lock pump/cam etc.
As said on this engine there are two belts, one drives the cam and the other drives the pump, the smaller pump one often gets neglected breaks and takes out the cam one when it tangles, so a cam kit with both at around £45 is best bet, also includes the tensioner etc.
Look at about 2 2-1/2 hrs to do all straight forward.
tabetha