Don't need to replace it. Find a second hand one will be fine. The starter motor from the RAV4 is the same starter motor you can find on the 3SGE engines off celicas and MR2s. Just replace it. It's cheaper and less labour.
No, they are not the same thing, but rather than just removing the solenoid from the starter motor itself. Replace the whole thing.
A new starter solenoid itself worth as much as a second hand good condition starter motor with solenoid. So I don't see the fuzz why not just replace both of them since they are attached to each other.
I went through 2 starter solenoids since I had my 95 RAV4 and both times I just purchase something from a wrecker in good condition and to heck with the rest. Not to mention you can have spare parts for later.