I took a look at Exmarks factory lift that attaches to the front of the frame. Then I went to TSC and got a trailer tongue jack ($25). I attached two sturdy hooks with nylon straps to the bracket on the jack that is used to fasten the jack to the tongue (if it was to be used as a trailer jack). The hooks are then positioned under the front center of the deck and the jack is cranked up, raising the deck a good 14"-16" from the floor, plenty enough to change blades and scrape the deck. I usually put a second jack stand under the deck of the Z just for safety, then shift it to the side opposite from where I am working.
For floating decks I use a wooden spacer laid on top of the deck under the frame rails to prevent crushing the belt covers when raising the machine.
Sounds more complicated than it is, but it is reliable, safe and very affordable.
Works for me.