Seriously go to a gym and get some forearm strength or something Or you could do exactly what everone else has said, PRACTICE Dagnabbit!!!!
Having trouble switching between the lowest strings is crap, a real guitarist would easily get over it. What a dumb and weak question you have proposed. The sort of thing that you should have figured out for yourself easily and simply solved the problem.
PRACTICE and you shall overcome. Do exactly as you have been instructed to do simple minor string skipping exercise. Or do this one.
------22----33----44-----55---
---00----11----22-----33------
Up and down the damned fret board over and over and over and over and over again until it sounds flawless.
I appologize if my brutal honesty and attitude offend you but seriously get over it.