Recently bought Diablo 2 and the dlc, cant find a way to install it

So i bought D2 and I was trying to find a way to install it, the battle.net app doesnt show it, but when i go to the shop on my acc it says you already have this bought… So i looked a bit on the blizzard web page and i found some kind of likns for an old battle net app and apparently i have to install the game through that but it wont install, it just gets to 99% and freezes. Sry about the english its not my first language

Hey Lex7,

You will need to install it by downloading the separate installer from this page. If you are using that installer, make sure you are running it as Admin.

ive done that and its telling me that i dont have the right permissions

can not access the specified device path or file may not have the appropriate permissions to access the item