My brothers 06 Nytro has a little dent on the bottom of the oil filter(due to a milk crate under the sled for a month last summer when i had the floats rebuilt).There was no leaking because he put 600mlies on the sled last winter,so my question is can the oil filter be changed without draining all the oil(oil was changed this past spring)or is it safer to remove all the oil in a clean container?Would really like to replace this filter so we won,t have to worry about it leaking.