starter question

I have a 96 avenger that has some starter issues it has 157000 miles on the starter. To get it to start i have to sometomes hit the starter to get the celenoid to pop out. I was wondering if just replacing the celenoid would work or if it would be better to just replace the starter. If possible to just replace the celenoid how hard of a job it would be? I'm just trying to save some money.

celenoid should be replacible, and should do the trick

yes you could replace the seloniod but with the mileage and year how much money and time will you be saving yourself when you gotta replace the starter in a month or so then its double the work and your out the price of a seloniod and a new part warranty in the long run its really not to price efficent

I dont know about Avenger starters: With many starters there are a couple of screws holding the solenoid to the starter frame, and they were probably tightened with an impact device. A hand held impact tool that you hit with a hammer might be needed to get those screws to loosen.
But the problem with replacing only the solenoid is that the starter itself is not going to last forever. If nothing else, its brushes may be quite worn down. Also it may have a good bit of hardened grease gumming up the commutator that the brushes ride on. For some starters you can buy a the brushes or the brushes and holder assembly. I bought such an assembly for the brushes in a Saturn starter, for $25 - from a place that rebuilds starters & alternators. The regular auto supply places didnt carry them.
While I prefer to buy my parts locally, you might want to check out buying a rebuilt starter on-line. Even with shipping it might be cheaper than buying locally.
My daughters 97 Dodge Neon had a starter whose brushes were worn down to about the thickness of a thumbnail - at 140,000 miles. The brush feed-wires were spotwelded to the connections, and one of the bearings had worn enough for the rotor to be rubbing against the stator - so I had to buy a rebuilt starter.