I was doing this not so long ago, not with custom time stamps,
It's a lengthy process and can't remember how I did it off my head unfortunately
How ever the least way to not get banned is to CFW them, Sync on OFW then Run back CFW and over ride permission and re sync on OFW, it was a lengthy process but I'm still not banned with over 80 platinum a

It took me about 20-30 a platinum