Rep Power: 224

This is all that's in the service manual. They should pull right off with some force. Shows a special tool being used.

 
Rep Power: 512

To remove them, I used a pair of ViseGrip groove lock pliers and a lot of "gentle" force and wiggling to get it off. I didn't find a way to take them off non-destructively, at least with regards to the valve seals. Just be careful not to damage the valve guide itself

To install them, I used my thumb and they clicked in place just fine. I didn't use any special tools for removal or installation

 
Rep Power: 0

I figured it out using the 9.99 valve seal plier from Amazon. What you have to do first is burn the seal with a torch or lighter until it starts smoking. Then use the pliers and it slips off easy.