Word files are generally frowned upon in this forum. A lot of members won't open Word files because of possible viruses in macros. Can you convert to pdf?
Very well, then. It looks like a straight-forward integration problem, then. You've got to plug things into things, and then plug those into things. So, for example, you have
Taken together, you've got
All I've done so far is plug into the expression for right?
Now, this is a doable integral as is. Do you know how to integrate Gaussian integrals?