to install this module simply follow the canonical procedure for installing any perl module

$ tar zxvf Apache-SizeLimit-0.XX.tar.gz $ cd Apache-SizeLimit-0.XX

$ perl Makefile.PL
For static mod_perl use -httpd /path/to/httpd For dynamic mod_perl use -apxs /path/to/apxs $ make
$ sudo make install

for further directions, see the README.