Oils and Massages for Scar Tissue

[Jezz]

Hi guys,
I had surgery about 5 weeks ago.  I've noticed under my left nipple, on the left side of the nipple, there's something hard underneath and it's puffing out a little bit.  I've read that this is scar tissue.

What oils can I use and where can I get them?
How do I massage it once I put the oils on?  Just with my fingers?  How often?

Any advice is appreciated

[dondante]

My ps recommended that I use arnica gel on my scar tissue by massaging the area for 5 minutes, 3 times a day.