Hello I own the A815 MID android tablet, The one sent to me was supposed to have 4g internal memory but sadly it only came with 1g. I have a 4g that will fit but my question is, where is the operating system installed at? Can I simply just replace the 1g for the 4g or do I have to copy information from the 1g to the 4g before I can swap them out? If someone can leave descriptive instructions on how to change these out, as in the operating system; I would be very appreciative. Thanks!