If you have the funds, you cannot go wrong to get a solicitor to guide your actions. But having experience with a similar situation, I would advise the following:
Don't just buy a one-way returning to Home Country; buy a full fare one-way with a flexible date, so that if advised to, you bring forward the date, turning right around and departing the same day without having to be refused entry, which would be bad.
Definitely, do not walk through any electronic border control, for instance an e-gate. When you do this, and the computer loads up your Tier 2 status, the act of you presenting your information tied to that status is technically the same as telling the UK that your Tier 2 status is unchanged. So, be sure to present yourself to the border agent personally! Ignore those purple suited do-gooders at Heathrow who might guide you toward any electronic entry system :)
Do not commit beforehand in writing that you are entering as a tourist, or as a Tier 2 holder or basically, do not commit in writing to any entry status claim. Just go open minded, and explain your situation in person to the border agent. In the UK the border officer has 100% authority to let you in or reject you, on a combination of their feelings about you and your case, and also the quality of any evidence you have on hand.
Perhaps you could say for instance, "Good morning, officer. I had a Tier 2 visa granted on $DATE, but on 13 December I lost my employment. So, I do not know exactly under which status I will enter the UK. But I wish to return to pack up my things, spending 48 hours here. I have a return ticket dated for $DATE, but if necessary I can change this date to earlier. I would like your help, please."
- Print out or obtain paper to justify or back up every single element of your situation. Your current UK address where you want to clean up, your work termination, your travel authorization to the home country, etc. etc.