WP Memory Limit, et al

Hi, I have the Highend theme and I cannot install the Jetpack. I’m pretty sure it is all to do with some system problems I keep having and hope to have fixed with this request. The system diagnostics Highend page tells me I need to increase the WP Memory limit from 40 to 64, the php time limit needs to be increased from 30 to 400 and the max input time needs to be increased from 60 to 300. Can someone help me with this? Thanks!

Anne Roecker