Deleting multi bar rest alters the whole format of the music

There is a 4-bar multi bar rest at the bottom of page 1 which I want to delete leaving the previous 3 bars (with cue) as the last bars on that page. However, when I delete the multi bar rest the whole piece is rescaled and I get several lines from page 2 moving onto the bottom of page 1. How can I stop this happening please.