Call the Load Event from one form after it has been loaded before

Question

How can a form load event can be called from 1 form to another? for example say I have two forms. And form1 is my main form and form2 is my ColumnListCheckBox form. The form2 does the loading when the main form is loaded but if you insert a refresh button so the user can manually refresh the form as well, this should also refresh the load even in the form2. How can this be done? Thanks!