Currently I have a setup where .php5 works as PHP5 and .php works as PHP4. I was wondering if there was a way so I could change it so a single domain uses .php for PHP5. If so please give me the steps on how to do it.
It really depends on how you have this set up. I suspect that you have PHP5 running as CGI and PHP4 running as an Apache module. You can search your httpd.conf and search for php5. You might see a couple of lines that look like:
Again, this is just a basic idea that might help you find the answer. There really isn't enough information to adequately answer the question. You might have better luck by contacting the person or reading the guide to whatever you used to implement PHP5 and PHP4 simultaneously.
Please Note: I would not copy and paste the above code segments directly as I have them, unless by some devine intervention what I mentioned is exactly what is in your httpd.conf file.