Watch the 5/4 Rush online guitar lesson by Jeff Scheetz from 50 Blues Rock Rhythms You MUST Know
Anytime you have something other than 4/4 time you will need to get adjusted to it. This riff gives you a measure of 5/4 then goes into two measures of 4/4 then back to the 5/4. Count it out until you get it and then really try to "feel" it. Once you have it down it won't seem so odd.