1, take the initiative to consult the old cashier. You can also pay a little money to invite him to dinner or something to improve your relationship with him. (Best strategy)
2. Help him and steal secretly. (Zhongce)
Complain to your immediate supervisor and put pressure on the old cashier. However, this will cause colleagues to have a problem with you, because he has been in the company longer than you and has a wider face than you. As a result, you just offended him. . . . Your immediate supervisor will also have a bad impression on your interpersonal skills. (worst policy)
I suggest you do the handover work as soon as possible, otherwise it will delay the work and the boss will doubt your ability to work. The general boss doesn't care about the process, only the result. Be careful.