How to swap buffers? - going from tris-hcl to potassium phosphate (Jun/28/2006 )

hello,
i have a protein that i am in the process of extracting and my elution buffer is a 75mM tris-hcl + 1mM CaCl2 + 1% sucrose+ .2% triton x. once the protein is eluted, i need to change it over to a 5mM potassium phosphate buffer. The enzyme is eventually lyopholized and sent to the other lab for use. they really don't like all the salt left over from the tris, so i come for suggestions
Thank you
cheers
dez

you can dialyse or diafilter.