Certainly you can do this. It is going to mean burning a lot of midnight oil between now and test day, however, you can do it! Plan on 10 hour per day on each weekend up to the test date, along with about 10 hours of study/review time during the week. Make sure the spouse understands the import of this activity-- tell the children why this is so important (if you have kids that can understand), then hit it hard.
There is no reason to take this more than once-- really study and understand the questions and what they are looking for. Remember, they are testing for the minimally competent engineer, the C- student. The problems are written to be completed in 6 min or less. Don't overthink the problem-- there are no "trick" questions-- they are all straight forward questions-- where many folks get goofed up is that they do not fully comprehend or understand the concept being tested and get out in left field and burn 30 min. If that happens, push reset and go on. Come back to the problem after you have worked several others-- it may be that the answer jumps out at you.
I have been on the IE PE test development team for 4 years. Some questions can take less time, some take more, however, the average is 6 minutes per question. If you know the subject, the answer should be obvious. Sure, there may be some calculations involved, but you know what calculations need to be made to derive the answer to the question.
Work LOTS of problems-- make sure that you understand what you are doing and not doing it mechanically-- really understand what they are asking you to solve. If you have been out of school some time, you may need more than 10 hours a week and 20 hours per weekend-- this will be rough for 8 weeks, but you can do it.
Buy an approved calculator and really learn all of the functions. I have a TI 30X-- nothing fancy, it is approved for PE tests. It works, however, you have to work it to recall all of the buttons and functions.
Good Luck-- I have great faith in your skills and abilities-- it will be HELL for 8 weeks-- OK, you know that now-- work like Hell and finish it-- take the wife out for a long weekend-- your wife and your boss will both be happy campers.