I want to resize my booted harddisk

My current booted dev/sda3 is 40 GiB but maximum size is 463 GiB. I’m running yast partitioner with dev/sda3 because that’s where computer boots. How can I resize it? How can I open yast partitioner before it boots?

You can not modify a mounted (ie running) partition. Use a live Linux device or from a second Linux OS if installed to resize.

To expand a partition it must have space available at the end to expand into. If in any doubt show use what you have ie fdisk -l ( use coed tags # in tool bar please)