If your phone is S-Off, then rooting is easy.

Download the official 2.2 update from Google:
http://android.clients.google.com/packages/ota/verizon_incredible/00cb7fa66e35.OTA_IncredibleC_Verizon_WWE_3.26.605.1_3.21.605.1_release_sign.zip

Download Clockwrok recovery:
http://solo.dc3.com/dinc/ClockWorkRecovery%202.5.0.5%20(PB31IMG).ZIP

Download Superuser: http://solo.dc3.com/dinc/su-2.3.6.1-ef-signed.zip

1. Rename the 2.2 update to update.zip and boot into HBOOT. (When the
phone is off hold down Vol – and then press the power button.) The phone
should detect the update file and ask if you want to apply it. Select yes.
2. After the phone reboots, remove the update.zip from your SD card.
Rename the clockwork download to PB31IMG.zip and put it on your SD card.
Boot into HBOOT and apply the update.
3. Reboot and remove PB31IMG.zip from your SD card. Put the su download
onto your SD card and reboot into recovery (go into HBOOT and select
recovery). Then, in clockwork recovery, select Install zip from card,
select file, select the file you downloaded, and apply it. This will
install su (super user, which is essentially root).

If for some reason the phone doesn’t prompt you to install the google
update in HBOOT, do step 2 first, then in clockwork recovery apply the
update.zip using the Install zip from card option. You will then have to
reapply clockwork recovery because the update will write over it, then
install su.

Good luck!