[flippant]

Be patient and point at specific "sloppy" things and explain why. If your colleagues are reasonable, eventually you'll help them up to your level.

[meltonian]

Agreed. This will help everyone in the long run. The less shitty code you have that can be copied and pasted the better.

Additionally, you may want to take a step back and see if you can implement/point to a style guide. Linters/code formatters might help with this some of the frustration.