String Parsing

I am trying to parse values out of a string. The source of the string is the serial UART.

String response(RxBuffer); 
//Rx_Buffer contains:
//User_Name: Ryan\nUser_ID: radensb\nUser_Password: passwd\nUser_Slot: 8\nUser_Number: 45\nUser_Time: 16543\n

I want to parse the response string to get the values:
Ryan
radensb
passwd
8
45
16543
and store them is their own strings. Normally, I would do a simple regex, something like:

Regex match = regex("User_Name:\s([^\n]+)");
if(match.success)
  string uName = match.group[0];

but that is not readily available in the Arduino environment, and I think it might be overkill to include a regex lib for this purpose.

What is the typical way of doing something like this?

I looked at substrings, tokenizing, even looping through the chars in the Rx buffer directly, however, none of them seem very clean.

I appreciate the help!

Check out strtok().