Hello,

I want to install usermanager package on RB951Ui-2nD (hAP). This package is not installed on this router as default.
I have downloaded "Extra packages" from http://www.mikrotik.com/download.
How I can install this package now?

First of all you need to replace the combo package by individual set of packages. Then you can select whatever package you need. Putting single additional package to combo package is not recommended by mikrotik. Search the forum for details...

Hello
RB951Ui-2nD isn't hAP and you can install usermanager on it.
you should download MIPSBE package and then install it on your router.
Good Luck

RB951Ui-2nD isn't hAP

Not true, aparently:

http://routerboard.com/RB951Ui-2nD

you is right.but that router is MIPSBE then you can install usermanager on it

Please See this photo

hap lite series is not support userman (CMIIW). you can use the third party application like The Userman. check this post viewtopic.php?f=10&t=123097