Weapon Upgrading

I havn't played enough to find these upgrading parts (hilts/strings/etc) but have seen enough posts about them...My question is;
Can you upgrade an already upgraded weapon, i.e: If i upgrade a bowstring, but want to use a different bowstring on the same bow at a later time, can I install it on the upgraded weapon (possibly destroying the old upgrade in the process).

I need the whole rundown. How to upgrade, what to upgrade with, how to tell if something has been upgraded, what can be upgraded.

I got none of this from the last two BWEs. It will probably be in the release paperwork, but I wanna know now.

Im with you guys. Is it hard or expensive? Do you have to find the upgrade items, or can they be purchased? Is it a strong factor of the game? I would really like to know.

A weapon upgrade can do a lot of things. It will tell you what it does.

For instance, if you put a Shocking Bow String on your bow, you just changed the damage type of that bow from Piercing to Lightning Damage. And if you put a Bow Grip of Defence on your bow, then you've got a Shocking Bow of Defence. Defence grips give about 4+ armour. There are lots more upgrades like this and you can usually have 2 on there. I'm not sure what happens if you try to put a Fire String on an already Shocking Bow which means "I don't know what happens if you try to upgrade an already upgraded weapon" ... but i don't think you can. Each weapon has 2 types of upgrade components.

Swords: Hilts and Pummels
Axes: Grips and Hafts
Hammers: Grips and Hafts (they have to be a specific "hammer haft" or whatever)
Bows: Grips and Strings
Staves: Wraps and Heads

you can't upgrade wands.

.... oh and some weapons already have weird upgrades on them which will not block you from putting your own on there. Like if you found a staff that had a +10 energy modifyer on there and you wanted to add some other stuff you could.

...yeah... you gotta find upgrades. the best way to find an upgrade is to use an Expert Salvage kit on an item drop that appears to have the upgrade compnent on it. Like if some monster dropped a Granite Hammer (granite = earth upgrade) and then I used an expert kit on it, I have a pretty good chance of getting a Granite Hammer Haft.

... of course, you can buy them from other players. the weekend before last I bought a Shocking Bow String for 30 gold... I have no idea what that translates into this beta weekend since they made gold much more available and items much more costly but it would be relivant. In other words, it's not a huge price but it's not tiney either and it'll probably grow as demand goes up and then get cheaper once everyone gets what they want.

Looks to me that theyre leaving the economy in our hands (for the time being) and this will translate into need vs availabilty. I'm glad they improved the merchant pricing in this last beta as I found it somewhat frustrating that everything was worth 1gp in previous events, but seeing the range in prices was quite funny, some folks selling dye for 700gp each, others for 10gp and anywhere in between. Prices will inevitably even out when the game is released as more people will have more items to sell....I'm getting off topic now...I guess I'll need to play the next beta and try to get some upgrading items and give this a go...and I hope they make wands upgradeable as my new favorite combo is the Me/E aka Caster's Bane.

weapon that already have an old part would only get replace by the new part that is using the same slot on the weapon.

now you dont need upgrade npc to upgrade your items... you just simply double click and then click on the choosen item.