I think it might help to look at what is driving the team member’s resistance from two perspectives:
What have you done to facilitate the knowledge transfer? Is the process easy? Is there an adequate amount of time for it? Is it structured so everyone knows what to do/when? Or, is it wide open so that no one is certain of anything? If it is, that’s hard to get your head around and it’s easy to put it off or procrastinate.
Is the employee retiring under duress or leaving on a positive note? If it’s the former resistance may be grounded in some difficult emotions. If the employee doesn’t feel appreciated/valued the last thing they want to do is teach someone else how to do their job. And, if you need more than one person to handle it all, the soon-to-be-retiree is upset bout being undervalued for so long.
The first scenario should be a relatively easy (albeit time consuming) task. For the bad blood scenario, I would speak to the employee or take him/her out to lunch and ask for their help. Explain how important it is for the continuity, and ask what the employee needs and what you can do to facilitate the process. I hope this helps!
Originally published in Quora