Changing Note Lengths without removing other notes
In the measure pictured (referring to Voice 1, the blue notes), I want to change the C to an 8th note, and the subsequent Bb to a dotted half note. When I try to do this I end up losing the other notes and have to re-draw them in. What is the correct step by step method to convert that first quarter note to an 8th note and "merge" the 8th rest that was created into the half note?
Thank you for your help!!