This is what you will need to do in Pre 2 before doing anything:
a. Goto into Developer Mode by typing "webos20090606", select Developer Mode Enabler.
b. When the Developer Mode card is opened, set the switch to "On" and select "Just Charge".
In Debian, do the following
a. Download webOS Quick Install (WebOSQuickInstall-4.04.jar) from http://forums.precentral.net/canuck-coding/274461-webos-quick-install-v4-04-a.html
b. Download PreWare (org.webosinternals.preware_1.5.0_arm.ipk) from http://get.preware.org/ which is listed in http://www.webos-internals.org/wiki/Application:Preware#Installing_Preware_on_webOS_2.0
c. Select "Applications" - "Accessories" - "Root Terminal" and you will need to enter your password.
d. Once in root, run "palm-install org.webosinternals.preware_1.5.0_arm.ipk" and this will install PreWare on webOS 2.1.
Basically, this is complete and if you want to install other apps through webOS Quick Install, you will need to install webOS Quick Install.
a. Under Debian File Browser, select WebOSQuickInstall-4.04.jar and right-click on it. Then choose "Open with Sun Java 6 Runtime". This will launch the webOS Quick Install.
b. To install, select the "Globe" and it will list all the apps, patches, tweaks, services, etc.
The other alternative is to run PreWare on Pre 2 (once installed). This will list similar stuff as per in webOS Quick Install. Personally, I would prefer to install through PreWare on Pre 2.