In theory, the toe-kick should pretty much just pull off, if your installer used the leg clips that come with the legs. These are "C" shaped rings that slide over and grip the legs enough to keep the t/k in place, but not so much as to keep you from removing them.
Because this is a "custom" t/k, the installer probably used sdome "custom" method to secure it - adhesive of some sort, or screws, or a combination. Your best bet is to call him and find out how he did it.
As for the plastic strip, I never use it. When it's in place, I think it looks really crappy and cheap. I think you're better off skipping it altogether. Just be careful with your mopping.