how to change default file manager

hello. my current file manager is the default nautilus, but I want to use thunar. how can I make thunar the default? i have install exo utils and selected thunar as default through exo-preferred-applications. however, this does not work. nautilus is still the default.

Try right clicking on a document:

Select "open with"
choose thunar

Select use as default.

aephlux thank you for the reply. this allows me to open thunar but not to set it as default. the use as default check box is not there.