I do not have a sofer stam near me. How do you open up your tefillin's battim and insure the parshiyot inside are kosher? I suspect they are not kosher (at all), because they are a really cheap pair. I am working to replace them. I have even stopped reciting a bracha on them because I don't think they are valid.
If the boxes are kosher, you should get a real sofer to check them. If there isn't one near you, you can call a sofer in New York and ask if you can mail them in. (Since you live in Midland) There is a sofer in Dallas. Contact Congregation Toras Chaim for his information.
To open the tefillin: You can open them up by cutting the sinews with a razor blade or exact-o knife. Pluck out the bits of sinew and you can open the top and bottom easily.
But to close them again you will need sinew. It needs to be from a kosher animal made by Jews and there is a special way of tying it.
The sealing of the top to the bottom I done with glue. It looks nicer and keeps out more moisture but is optional. It can be done carefully with a fine razor.