Neither 0000 or 1234 work as Motorola t305 passwords

I wasn't able to locate any documentation on a factory reset, but if it is like all of their headsets, press and hold both volume buttons and the call button at the same time - hold it for 10 seconds and it should reset - IF it works the same. If it does, the default passcode is 0000

Reset button is a small soft rubber circle near the on/off button.

Hard reset for motorola t305:
1.Open the device. take the two rubber covers on the back to get access to the screws, take the screws off. The unit does not have tabs to open so you need to squeeze it on the round side sideways to force it to open, use smal screwdrivers to help.
2.When you get access to the inside grab a piece of stripped tips wire. Find on the top side of the board a trace that has no enamel on it, its bare copper.
3. Short the strip with the copper strip that protects the battery, it will cut off the power supply from the battery to the circuit giving the unit a hard reset.
4. Carefully assemble the unit and pair it again.

I tried both solutions above and I don't know which of them it was, but my device reset back to 0000. Cool.