Hi
" That will cut the rest of the video to the end? "
No. Using the IN/OUT markers is CLIP SPECIFIC. It doesn't affect the whole video. This means you use them in CLIP PREVIEW for selecting a piece of a clip between the markers... The highlighted section of the thumbnail line under the clip preview pane can be inserted into the timeline using the green PLACE button. If the clip you are editing is already on the timeline the edit is automatically done by VP..........

If the section you want to remove is just at the start or end of a clip you will only need to set one of the markers. The example above shows both markers being used to select a centre portion of the clip.
If the unwanted section covers more than one clip, you can either deal with each clip individually as above or split/ select/delete the unwanted portions and close the gaps produced directly on the timeline as describes in the earlier post.
Hope this helps
Nat