I need to remove "Memberlist" and "Usergroup" from my main menu.

Forum url: http://www.bdtipsntricks.com/
Version: punBB

Add this to your CSS:

Code:

a[href="/groups"], a[href="/memberlist"] {
  display: none;
}

:D:

Working but, there is an odd gap between two link. Here is a screenshot.

Yep. You need edit it's order. Go to ACP > Display > Homepage > Headers & Navigation:
- Click the image (order) until those 2 navigation go on the very top.

They should be something like this: (They should be the first 2 in order)

Great! It's totally solved. :D:

Welcome. Since the problem is solved, i'll locked this and move to archive section. :D:
~ Locked and Moved