What is the best way to get the values in the request-uri into the body of the invite, then delete

What is the best way to get the uri-param into the body of the invite as shown below, then delete them from the req-uri? Thanks.

INVITE sip:+1111222223333@1.2.3.4;field1=value1;field2=value2;field3=value3;field4=value4
From:
To:
Call-ID:
field1: value1
field2: value2
field3: value3
field4: value4