I previously had installed php 4.3.4 from source. Now I want to install php 4.4.2 using the slackware package. I installed the package, but when I type php -v, it still says it is using 4.3.4.

1. how to I remove the php that I installed from source? There are several threads on here asking about it, but no one has been able to give the correct way to uninstall. make uninstall doesnt work, and I can't find anything on the php website.

2. How to I get slackware to use the package installed version instead of the source installed version?
When I try to start apache, it says:

Syntax error on line 6 of /etc/apache/mod_php.conf:
Cannot load /usr/libexec/apache/libphp4.so into server: libmhash.so.2: cannot open shared object file: No such file or directory

But, the file exists...

ls /usr/libexec/apache/
total 4240
drwxr-xr-x 2 root root 4096 Feb 14 13:01 .
drwxr-xr-x 7 root root 4096 Feb 14 13:00 ..
-rwxr-xr-x 1 root root 4320112 Feb 14 13:01 libphp4.so

For uninstalling maybe you could try this:
Get 4.3.4, compile and make slackware package. Uninstall 4.4.2, install 4.3.4, uninstall 4.3.4 (at this point no file of 4.3.4 should be left), then install 4.4.2
Talking about libmhash, check if this file exists in original 4.4.2 package.

if you haven't remove your PHP source directory, try running make uninstall, but i don't guarrantee this will works, since i have never tried this before, since i always sticks to source code packages because i need different modules which Pat has compile for the PHP packages in Slackware

He said that make uninstall doesn't work.

What do you mean by compile and make slackware package? Is this different than making from source? Or do you mean install the 4.3.4 slackware package?

It appears to me that the files installed by the source install are different than the ones installed by the package, probably because Pat uses a different install directory than the standard source install.