A hint attack it with parafin or some type off cleaner, also think about making a list off all the screws and buy decent ones, that will help you in future when one rounds ,and you cannot get it out cheap but worth while, also i fitted ballraces and thrust bearings on the lead screws again very cheap but improved the machine dramaticaly, they are a good machine as they come for the price and size, but rember it does have limitations but most things can be done with a bit of thought, oh and buy some extra fuses the right size, dont put biger in as the power supply is a dear as the mill to buy ( nearley)
Happy Milling
Peter