This is for STOCK ROOTED phones only!
Custom ROMs will need to be patched by their devs.
This also assumes you have S-OFF applied.
1. Get the OTA:
http://android.clients.google.com/p...on_WWE_3.26.605.1_3.21.605.1_release_sign.zip
2. Get ClockWork Recovery:
http://downloads.unrevoked.com/forever/recovery/clockworkmod/PB31IMG.ZIP
3. Get these two Su utils:
A.
http://www.unrevoked.com/incredible/payload-update.zip
B.
http://bit.ly/su234ef
4. Copy the OTA (the first download) to your SD card.
Rename it Update.zip. If there is already an Update.zip on the card, remove it.
5. Get "Quick Boot" from the market and use it to reboot into Bootloader.
6. The bootloader will find and install the OTA for you. This can take a while and will finish after the phone reboots.
7. Now copy the ClockWork recovery (second download) to the phone.
DELETE the previous file (named Update.zip)!
8. Use Volume/Power buttons to boot into Bootloader again and apply the update (it will ask you).
9. Boot into recovery and test that it took.
10. Reboot back to the phone and
delete PB31IMG.zip.
11. Copy the remaining two files to the phone.
12. Use Volume/Power buttons to boot into Recovery.
13. Select apply zip file from SD card (the option that lets you choose the file, not the one that automatically installs Update.zip). Select and install the file beginning with "SU-2.3".
14. Repeat 13 installing the payload-update file.
15. Reboot.
16. Joy!!!!!!
You should now have the same settings/apps/data you had before, but also have the OTA and root.
PS - Side effect of the OTA, you also have double everything on all of your home screens. Try to remove something, anything, and you will see what I mean. You have to remove every double or things wont work right.
Enjoy!