How to add more notes to a measure?

Hello,

I tried to find the answer, but it seems that all answers are related to grace notes, which is not what I'm looking for.

Here is one situation in the attached picture, where I need to add more notes to the treble clef which is impossible since MuseScore thinks it will exceed the 4/4 timing. Basically I need to play the last four 8th notes using the right hand (which would then let the left hand to take care of the next measure's half notes by passing over the right hand), so I want these four 8th notes to go into the treble clef as apposed to the base clef where it currently appears (with numerous leger lines which is cumbersome to read). So, how can I do this in MuseScore?

Thanks much!