The stuff you're trying to download from SourceForge is source code which would need to be compiled. Rather than mess with it, there's a prebuilt Slackware package of tcltls available from Alien's directory at slackware.com. Here's a quick link for convenience: http://www.slackware.com/~alien/slackbuilds/tcltls/pkg/11.0/tcltls-1.5.0-i486-1.tgz
Once you've downloaded the package, open a terminal and become root via the su command. (Make sure that amsn is not running.) Once you are root, type the following:
This assumes that you are in the same directory to which you downloaded the package.
Now try running amsn. You should be able to get in.