Transfer at Paris (CDG) from terminal 2E and 2D by foot is possible?
 

Im flying from Rio de Janeiro to Helsinki with a connection at Paris CDG, which means flight from non-Schengen area to Schengen area, I'll arrive at Terminal 2E not sure about the gates yet and then take my flight to Finland at Terminal 2D, I have 4:20 hours to change from one terminal to another, can i do it all by foot or I'll need to get those buses and what would be the easier way to do it? I really dont want to use buses cause I'm afraid of getting lost. Also I saw that there's not a passport control at Terminal 2E and I have to go through it to exit that area and move on to 2D, right?
Thank you in advance!

It's not a difficult walk at all. You have more than enough time to do it.

Chances are you will be directed through Passport Control in Terminal 2C. The easiest and most comfortable walk is through the hallway over the train (SNCF) terminal and under the Sheraton Hotel. (It's been a while since I did that, and you may end up going through the Sheraton lobby itself.) Just go right from the passport control exit, left towards the signs for Terminals D and F, and left again when you reach the walkway between the terminals. It is far easier than the bus trip, which would take you to that same intersection between the two terminals.

Just follow the signage. It was improved a couple years ago and now is pretty clear.

Thank you guys!
I have another question, does anyone know if I have to go to the immigrant control on the way back to Brazil? Since it's Schengen area to International flight I believe...

Yes you'll need to go through passport control at CDG to exit Schengen.

The change of terminals is super simple. Confusion in the past was due to a minor cultural difference. Europeans often look for signs at eye level. People from other continents apparently need to see signs hanging from the ceiling.