Hi, Kimagine, I'm glad that I'm not the only person that has bother attaching a walking foot. I have a Janome DHL603 and it is a super machine, but every time I try to attach walking foot I have a terrible job.
If I magnetise a screwdriver I can just about manage to put the screw in. Someone suggested to me to partially loosen the screw and this does help. Hope this information helps. Welcome to the site.