How can I automatically change all the remaining parts into full 4/4 measures when I split the first 4/4 measure?

Hi, Could you do me favor? I typed up a sheet music, using MuseScore before. Now I'd like to split the first 4/4 measure into 1/4 measure plus 4/4 measures for all the remaining notes, which means I need to pull all the remaining notes in order to make full 4/4 measures. I've followed the instruction of Handbook but have no idea how to change all the remaining notes into 4/4 measures. Please do help me how. I'd appreciate it.