I was wondering if there is any huge difference between the N810 and the N810 WiMax edition. the only difference I can see so far is just the wimax partand the price. Also, is there anyway that the N810 can use wimax, or does it need some special antena-ish thing?

Yes, WiMAX support and price are two of the major points of difference. The others are probably the case color scheme and the default theme.

Beyond that, there are some less immediately obvious differences:

• The upper back panel of the WiMAX Edition bulges outward slightly to make room for the WiMAX antenna.
• The WiMAX Edition has fewer Bluetooth profiles enabled out of the box. They may be enabled by the manual editing of system files, but Nokia disabled them due to interference between the Bluetooth and WiMAX radios.
• The WiMAX Edition uses a different model code from both the N800 and N810. Therefore, programs that check the model code to adjust to differences between tablets don't know what to make of the WiMAX Edition until the programs are updated.
• The WiMAX Edition uses a slightly different system on a chip than the plain N810. Technically, it supports a few extra features. That's invisible to users and even application developers though.

You'd need an antenna and a WiMAX chip. They can't really be added.

- The WiMAX Edition has fewer Bluetooth profiles enabled out of the box. They may be enabled by the manual editing of system files, but Nokia disabled them due to interference between the Bluetooth and WiMAX radios.

--------------

Is there anywhere instructions on which files have to be modified?

A simple search turns up the thread, "Bluetooth headset (HSP) on WiMAX edition?".