The rear differential is leaking on my vehicle. I'm concerned as to the current level of fluid inside.

The dealer is quoting me around $1500 to change the side seals that are apparantely leaking. When I asked if they could just top it up just to be safe since I do not want to spend that kind of money. I was told no it can't be done without all the extra labour. I find that hard to believe.

Can someone tell me how long a job it is to drain and refill the diff without actually changing any seals. I don't care so much about fixing the leak as I do about making sure it has fresh full fluid inside.

Do I have to take out all the bolts around the diff or is there a drain plug? Do I need any special tools?

If I have to take out all the bolts around the diff and separate the pieces, then do I need a special sealing compound before I put the two pieces back together?

Thanks in advance for any feedback.