The tool should be easy enough to use, nodejs wsproxy.js
To view the requests, a webserver is started up on https://127.0.0.1:8082 by default. To disable this webserver, change webserver=true to webserver=false in wsproxy.js. To create custom mangle rules, modify "mangle" in wsprocessor.js. Replace rules also get applied here. Replace rules can be hardcoded in wsprocessor.js or altered at runtime through the web-interface.