I am not an expert, but her Majesty’s firebreathing Danish Army did train me on a few types of the ugly things.
They’re nowhere near as dangerous to plant, it’s depressingly easy.
It depends on the mine type and the terrain. Your basic pressure-type anti-personnel mine is just armed and placed in a pre-dug hole - the smaller types fit neatly in the depression you can make with a sledge-hammer blow to the soil. Depending on the amount of vegetation, you can just put them in a shallow hole (having the plunger slightly above round level) or you can put a bit of dirt, sod etc. over them. Activation pressure is 1-5 kg, that’s quite a bit of dirt.
Tripwire mines aren’t armed until the tripwires are in place and you can verify that they’re not pulling sufficiently on the detonator system. Only then is a safety pin removed.
One major difference betwwen planting and disarming mines is that when you plant mines, they’re fresh out of the box and known entities - when you demine, the mines might be rusty, wet, cracked, halfway activated.
Some types are armed as soon as they’re assembled in the field. Some types have a grenade-like system where you have to remove a pin or spacer, or have to twist the two halves of the mine body. Some fancy types have a delay mechanism and arm after being deployed, when the troops are out of the way. As for dirt, it takes quite a bit of pressure to detonate an intact mine. You’ll have to work a bit to have two pounds of dirt on top of your mine. Most will put just what’s needed for camouflage.
They’d be hurt, sure enough. And if anything can be done wrong, I’m sure tired, hurried grunts will find a way to do it.
I know that for one specific type of anti-armour mine, we were warned sternly against swapping the screw-on activation plates between mines if we dis-armed and re-armed them - apparently some activation plates could be screwed in just a tad too deeply if they weren’t matched with the original mine bodies. With unfortunate consequences. One wonders how they got that bit of trivia.