Do you want to up-sample the data or just change the field of view. In the later case, fslroi would be the command you are looking for. To change the resolution of the data, AFNI's 3dresample would be a more convenient tool.
I want to change the resolution of fMRI in FSL from(72,72,10) to (64,64,10). Who could tell me how to chang the resolution in command or there is GUI that work. Thanks a lot ahead. I appreciate it greatly.