How would you install suPHP on a cpanel server

suPHP is nothing but phpsuexec in cpanel

You can enable phpsuexec either using apache update in WHM or using easyapache

Login to WHM as root

2. Click on "Apache Update" in the left hand column
3. Click on "Load Previous Config"

4. Check "PHP suEXEC Support" towards the bottom of the screen

5. Click on "Start Build" and let the installation complete.

or

Using /scripts/easyapache

Select option 6
Check the box PHPsuexec
select the php modules and start recompliling

+restart Apache