Short answer: You can't!
From How can I switch language in google play?, you used to be able to work around this via a proxy:
Basically the market is determined automatically based on your IP. You can change some local country settings from your Gmail account settings but still IP of the country you're browsing from is more important. To go around it you'd have to Proxy-cheat. Check out some ways/sites: http://www.affilorama.com/forum/market-research/how-to-change-country-search-settings-in-google-t4160.html
For the current versions of Google Play, it will always go for your IP address and geo-ify it. Therefore, if you're really determined you can use VPN to route through some servers with Geo-IPs.
If VPNs are not a solution for you (They weren't mine: Too expensive, too risky and depends on trust of the host, ...) you can mess with a GeoIP database (and have Hong Kong become US), alike as this XKCD comic:
If you're a fan of Google products and want to keep using it, you will have to deal with it, or use the web based market as pointed out in another answer. What I did instead was that I rooted my phone to remove Google Play store after installing Amazon app store, and used it instead.