Under Unix at least, switch to the directory you compiled perl in and rerun `make install'. When it gets to the part about "make this version active" or "link ... to this version of perl" answer yes.

More specifically, or if you installed a pre-built package under Unix, you can usually do a `which perl' at the prompt and get an answer like "/usr/bin/perl". Looking at `ls -l /usr/bin/perl*' should show the "real" perl as well as possibly other binaries. If there is a "perl5.6.0" then you should be able to do

cd /usr/bin
cp perl perl.5.005_03
cp perl5.6.0 perl
[download]

And get up and working...

--
$you = new YOU;
honk() if $you->love(perl)