Hi Possom,
Lill here, mince the fat, put some in a pan and heat, don't put it all in at the 1 time as this will take ages to melt down, better adding a wee bit at a time, when fat has melted put through a flour sieve, this needs to be done when the fat/lard is hot, the fat will drain through and the scum stays in the sieve, if any goes into the fat all you need to do is sieve it again, the lard can go into butter dishes, wee trays, i buy wee plastic dishes from tesco, put in fridge and leave to set. The lard can also go into freezer and it will keep for ages. The scum and be rolled into balls and used as bird feed. I do not put anything else in with the lard, but princess piggy put some ingredients in when the lard was runny.