getting ready to put some fresh oil in the forks. i have to remove them to install new head bearings anyway so i figured why not. gonna go with 10wt. so i have changed oil and rebuilt forks on street bikes and hd but i noticed no drain on these. gotta take them off and drain them. is there any special type of tools i need to use. any spring compressor? and i dont have a manual so what is the cc/ml fluid volume per tube and the air gap measurement.