I will try to help you, although I am not a system administrator.
Yes, it appears that you need to increase maximum execution time. Here would be my method.
1) Find out where php.ini is on your server. Do you have rights to edit it? You may have to switch to "root" to edit it.
2) Once found, edit php.ini. Of course, you need to know how to edit a text file in Unix.
3) Find the line below, and simply change its value. I like to use 600.
max_execution_time = 600
4) You might consider other changes, such as
max_input_time = 200
5) You may need to reboot your server for these to take affect.
I think that this is about all that you need. Maybe someone else can verify what I suggest.