@danielo5:
Download the .tar.gz version of the flasher tool. It's for Slackware and other Linux x86-distros that aren't .deb-based. Presumably you know how to install a .tar.gz file on Slackware, but if you don't it's as simple as 'tar maemo_flasher-3.5_2.5.2.2.tar.gz'.
Then follow the instructions on the wiki link. If you follow certain links there you'll find the flasher tool too. At one point you have to provide a code, that's the IMEI code of your device (just the digits).