"Google is your friend" I searched your question, as I dont know the answer.
Here's what I got first try:
(From ClubLexus - someone asked the same question in 2014):
The rear mount takes about 20 minutes. Here is how I changed the front 2. The mounts themselves are not cheap approximately $500 for the 3 of them. I wouldn't try aftermarket mounts. I think it took me 9 hours to replace the front 2 mounts. https://www.clublexus.com/forums/ls-...placement.html
It looks like a complkcated job, remove subframe, steering rack etc... But have a read, and google around.
What about a local mechanic rather than the toyota guys? Ask around
