How do I merge two identical names?

Which is the correct spelling: Alan Heillig (with one L in his first name), or Allan Heillig (with two L's in his first name)? And if Alan with one L is the correct spelling, did he happen to be credited on "A Year in the Death of Jack Richards" with the two-L spelling "Allan"? (The latter question could make a difference for how the name correction should be done.)

Please post exactly what you tried doing, step by step, and what error messages you got, and that will make it easier to figure out the problem.

Good luck!

Hi, thank you.
It's my bad, I thought the names were identical.
Alex