It really depends on your level of experience when working with motors, or anything else mechanical for that matter. There are specifications and tolerances that critical when dealing with the bottom of the motor. if you do not have the proper tools, or knowledge to do the job properly you might as well not do it at all. However, if you are knowledgable, and you have the tools, or you have a fknowledgable friend who would be able to help you through the process then I see no harm in attempting to do it yourself. Even if you see nothing wrong you could put the pan back on and send it where ever it needs to be sent to, if you decide to buy a new one.
If it turns out that you don't need to send the motor back when you buy a new one, and you've never broken one down before, it would definitly be a good learning experience to dig right in there, and check everything out.