You can cheat a bit (only a bit because they're very similar knots) by tying the snell down the shank with a uni. The other thing that is almost imperative is that you use a bit of red whiting tubing to protect the main line. This also allows you to snell the slider on really tight so it holds position in the bait but is still free to move with pressure.
So, slide the first hook up the main line with the line through the eye. Slide your tubing on too, and hold it parrallel with the shank. Take a second peice of mono, and make a loop ala uni knot and also hold that parallel, have the short tag at the eye, and a longer tag towards the bend. (I always use lighter to make it easier to tie and to keep the knot neat - it doesn't matter if it breaks, as it is still connected to the main line and stopped by the fixed hook). Now wrap the long end around the shank, tubing, and line cross-over towards the bend. at least 6 wraps, but you can keep going as far as you can. Wet and tighten. prob best to use pliers, not your teeth, as you'll have a hook point close to your face! Then just uni your fixed hook on to your main line.
Pretty simple once you've done it a few times. A second pair of hands can help to tighten the knot too, as it can be a bit hard to handle it all and co-ordinate the tightening process. As with all knots, practise on the couch in front of the TV until you're confident.