how do i install dlc for witcher 3 ?

Could you give less any information? Are you downloading via browser or Galaxy client? If its browser then download each file given on your account->games page, and then double clik on them to run them. If its Galaxy then I can't help as I wouldn't have that crap on my machine.

could you not be an ass and answer the question with out the unnecessary attitude ?

How is he being an ass? There are several different ways to download and install in here depending on what you are using.

You didn't even tell us if it was PC or Mac. How are we supposed to help you?

Open this page: https://www.gog.com/account
Search for Witcher 3
Click at the game icon.
Download the files.
Galaxy is not required.

I think he meant the "Galaxy is crap!" part, which I agree was unnecessary (and is even more irritating for those of us who see nightcraw1er post the same thing every. single. time. he sees somebody mentioning Galaxy, or downloading/installing their games, or the weather, or...).

On the other hand, the OP certainly could've mentioned whether or not he is a Galaxy user, as that makes a big difference in the answer.

Yeah, I can't argue with you there. I hate Galaxy but it was unnecessary.

Damn right! How dare that filthy worm not read your mind and know what you meant?

No need to escalate this more.

can someone plz tell me how to preload blood and wine using gaxaly on windows 10 thats all im asking . i will close thread after

They haven't announced any pre-load for Blood & Wine on GOG (nor did they for Hearts of Stone, as far as I remember). You'll have to wait for the release.
I imagine it will auto-install when it releases tomorrow, though, as long as you have Galaxy running and auto-update enabled.

Its hardly every single time I see a post about galaxy, otherwise I would be posting in every other post which appears on here, "why is galaxy broken <insert whatever>" every two posts.
As.for the first line of the post, that is this crap phone I am typing the message on - yes its a crap phone, no I am not posting everytime I see a post on phones about it - which is why it doesn't make much sense.
The main page of that dlc states 31may release date, things come out on different days on different os's I suppose.

I think he assumed a release date at noon GMT+1 tomorrow and counted it himself.

Extra necessary QA, maybe, since the PC version has to run on many different configurations.

Also, who knows, maybe they were trying to release simultaneously but could not predict how long Microsoft's certification process on Xbox would take and it was released as soon as it was ready there while the PC version (which they have full control over) is sticking with the originally planned release date or something.

Haven't seen a specific time mentioned anywhere, just the date.
As far as someone else having a countdown...you can make your own, too, if you want. That doesn't make it official. ;D