2005 LJ Belt Tensioner

Started the Jeep this morning and had no power steering. Looked under the hood and the serpentine belt was not moving.... Shut engine off and noticed that the belt tensioner has broken, the cast piece holding the spring has failed, so no tension on the belt.
Did a quick search and it's either a hex had bolt (which it isn't), or a Torx bit bolt (which it seems to be).
However, and it took a bit to get my phone in there for a picture, there is no place to insert the Torx bit. There appears to be the outline of Torx bit shape, but there is no way to insert a bit. I will try to post the picture in a minute.
There actually appears to be tool marks on the edge of the bolt almost like someone put a vice grip or pipe wrench on it. I am the original owner, I have never replaced the tensioner nor ever worked on it. Seems odd...
Anyway, any suggestions for removing it? Pipe wrench?


Thanks,

Erik