there is many tools for this but unfortunately all in unix operation system
1- Hex2Inject http://hexinject.sourceforge.net/
2 - ProxyShark http://code.google.com/p/proxyshark/
3- Scapy www.secdev.org/projects/scapy/
4 - mallory https://github.com/intrepidusgroup/mallory
5- netsed http://silicone.homelinux.org/projects/netsed/
all these tool are capable to modify
(edit) any packet
of any protocol
on the fly
then re send
it on the wire
and this is MAN IN THE MIDDLE
Note : for http/https/ws
fiddler should be the best debugging tool for http/https/ws(web socket) traffic http://fiddler2.com