x type power steering

[PJM5L]

my x type 2.0d has a leaking pas pump. Is it possible to replace only the seals? I am mechanically able and have tools, it's getting the seals that might be the issue?And does the pulley 'pull' off the shaft? Does anyone have any experience in doing this refurbishment. The pump works fine and isn't particularly noisey so paying out £120-£180 for a new pump when seals for a few coppers might fix it?