I don't know the device, but usually you can get into the bootloader by rebooting the phone while pressing some combination of keys. The precise key combination varies between devices and manufacturers (e.g. on HTCs reboot while pressing "volume down" does it, I think you use "volume up" with Samsungs, etc) so you may have to experiment a bit.
Once in the bootloader you should be able to navigate to recovery, which will let you do a full factory reset of the device.
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Edit: A quick web search turned up a couple of posts suggesting "volume up + power" as the combination, from off, which will get you to the recovery menu.
One person suggested that the device might have a reset hole on the side, in which case inserting something thin into that would let you do a reset. Do make sure that if you find such a hole it is a reset hole and not a microphone - pushing needles into microphones isn't good for them! The device's manual should tell you whether it has a reset hole (phones generally don't have these, but tablets sometimes do).
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I'm assuming that you currently can't get it to boot up. If you can you should be able to do a reset from the phone's settings (again, precisely where in the settings will depend on the phone - if you can't see anything that says reset in the top menu look for stuff like "privacy", as it may be hiding there if you have that).