I always just push it in by hand and have never had an issue.  Some seals come with the clips already attached to the rubber. That is the only way to go.

I like the idea of the pliers. Seems the tab that goes into the rubber breaks first...

wsinsle wrote:

Are they using to big a clip for the size hole it was intended for. If I remember correctly (thats asking alot) mine poped in fairly easy. I think I use 3M seal glue, the clips just helped hold it until the glue dried.

I don't think the legs on the clips are too big.  The slot the clips go into are a good 1/2 in long and the legs of the clips are anly 1/8" wide.  The legs are in a "V" shape that are supposed to push together when you force them into the slots.  I just think the "V" is either to wide or the metal is to hard and breaks when drove into the slots.  I called Mustangs Unlimited, where I bought the seal, today, but we have been playing phone tag.
 

MWM wrote:

Please let me know too, I have broken the clips on three different ones now and have put this off fir fear of breaking another. It's a Daniel Carpenter part too.

I sent an email to Danial Carpenter and got a nice response from a lady, Lisa Banks.  She stated they were pulling those parts off the shelf, so they must have had other reports of problems.  Anyway, she told me to contact Mustangs Unlimited, where I bought it and ask for a refund.  She told me to mention that I had cooresponded with her and she would honor the refund.  Her phone is 704-786-0990 if you are interested in refund for yours.