Changing sixteenth notes into eight issue

I am trying to change my score. At present one of my measures has an eighth note tied to two sixteenth notes, then two more eighth notes. When I delete the sixteenth note don't wan, it adds a sixteenth rest rather than making the remaining sixteenth note an eighth note. What I want are 4 eight notes. I've tried everything I can think of. Is there as way to do this without deleting the entire measure then adding in a measure with what I want?

Thank hyou