This was done on a 2900 but applies to all the switches of the same era.
Step 1 - Power Cycle and enter recovery mode
If you have physical access you can power cycle and hold the mode button down for 15 seconds. After that the SYS light will flash on the switch and you will see the following screenshot.
If you don't have physical access (eg. it is a datacenter swich over console only) then power cycle and hit "Ctrl+Pause/B........
This works on the 2000 and 3000 series generally.
*The easy way is to just hold the mode button for 10+ seconds.
The full/proper way is below:
1.) Either power on the unit and hold the "mode" button or hold the "mode" button until you see the below:
00:04:08: %SYS-7-NV_BLOCK_INIT: Initalized the geometry of nvram
00:04:08: %EXPRESS_SETUP-6-CONFIG_IS_RESET: The configur........