The ID is a Guid plus an additional identifier:
The identifier is composed of 20 bytes and includes two items: the machine Guid of the sending computer and a unique identifier for the message on the computer. The combination of the two items produces a message identifier that is unique on the network.
So there's no build-in parsing/reformatting function that I know of.
If you want to "parse" the guid part of the string to reformat it, you could do do something like:
string id = @"{5EADA58F-C733-48C3-A52A-A9FA749E7ADF}\2063";
string[] parts = id.Split('\\');
Guid g = Guid.Parse(parts[0]);
string newID = String.Join("\\",g.ToString("D").ToUpper(),parts[1]);
You might find that more "elegant", but it seems heavy to just remove a couple of curly braces.