CSharp -Converting IEnumerable to List or normal array for some short codes

I have some lines of short code containing IEnumerable in my csharp code.

Since IEnumerable is difficult to read and to modify, I would like to replace IEnumerable to List or other simple arrays.

I will provide the source code when you want to work on this job. You just need to send me back with the working code without IEnumerable.

For experience coder, this would be 20 minutes or 30 minutes job I guess at maximum do not take longer than 2 hours please.