When I replaced the Speedster emblems on my front fenders the new emblems had the posts in different locations. I removed all posts except the ones on the big S. I left that one to locate the emblems.
I tried using what I think is called adhesive transfer film. You press the emblem against it and adhesive transfers from the film to the emblem. That worked for a short time but the emblems loosened and looked very messy.
I thought about using mounting tape but wasn't enthusiastic about cutting the tape around the emblem.
Then I found these guys: http://www.adhesivetemplates.com.
They laser cut the tape to fit your emblems.
The cost was very reasonable. And, in my case, they even picked up my emblems.