Well, rip the magnet off the basket and glue it to your ladder.
Screws will be nice and handy and stay in place wile you scoot it around.
Step 1: You're Already Done!
Unless you want to know that I used just a dab of hot glue so it is semi-permanent.
Or that I used a hammer and a flat head screw driver to separate the basket and magnet. I don't know. That's what the comments are for. Magnets rule.