2002 Saturn Vue Question: Difficulty of replacing clutch slave cylinder

Yes, the transmission must be removed to replace the slave cylinder. This looks to be a rather big job. It may be a good idea for you to pick up a shop manual for your 2002 Saturn Vue. The shop manual should give you a good idea of what to expect when removing the transmission. I would also be a good idea to have a look at the clutch while you have the transmission out. I would also suspect that this job becomes more difficult if you have the all wheel drive system on your Vue.