where can i find a diy for arens belt replacment?

[berbes]

i have a nice arens intek 21", with a great b&h 6.5. when i noticed after sitting out the winter, the self propel didn't work at all in the upper speeds and looked, the belt that drives everything was a bit loose. for the life of me i can't figure out how to replace this belt. it's just not visually user friendly .

where can i find some kind of diy w/ steps to to this. pics would be a bonus!

thanks, folks!

[berbes]

well, i guess it'd help for searching if i spelled ariens correctly