Hide links in menu

Hi. my problem is with site https://offcorner.nstrefa.pl/whats/
I want to hide top menu

* to the beginning
home
* your own
profile
* friends or group
activity
* you can
create group
* your and others
groups
* inbox or compose
message

whitch is a link list to buddypress. Menu is not a plugin or widget, simply text links, and i know i should modyfy header.php but i dont know how. Please help me with that.