I'm new to blender and I want to use it as 3D printing software. I'm using 2.8 so I'll get used to new interface, but I don't know how to change edge length to a specific value. I know how to change whole object dimensions like cube, I'm using metric system and I can see edge length when selected, but how do I change it?
I found this addon and updated to 2.8. I think this is what you're wanting.
I am not at my computer right now, so cannot confirm, but Blender internal addons should have been properly ported to 2.80, so I believe the "Mesh: Edit Tools 2" trick should still work: How to set a specific edge length numerically? have you tried that?