Can an E4255 Duramax phone be unlocked from Sprint service?

when a phone is locked into a service provider but you want to change to another service provider , the lock is a contract that you sue only that provider
to get it unlocked , normally requires a payout fee of the contract to the original provider
contact them direct and discuss what can be done

contact sprint

Sprint phones

• CDMA carrier
• Uses 800MHz and 1900MHz spectrums primarily (bands 26 and 25), and 2.5 GHz for Sprint Spark (band 41)
• Does allow devices to be used on selected Sprint resellers such as Ting
• Phones will not work with Verizon
• LTE devices and iPhones may work with GSM networks, although service possibly limited
• Still not an 'unlock friendly' carrier

Sprint has recently launched a 'Bring Your Own Device' campaign for selected MVNOs (smaller wireless providers who operate on its network).
This means that some (not all) Sprint devices will be able to be used on either Ting or Boost Mobile (unfortunately, Sprint's prepaid MVNO, Virgin Mobile, doesn't accept phones from any other carrier - you'll have to buy a Virgin Mobile handset to sign up for service).
Outside of carriers on the Sprint network, taking your Sprint phone to Verizon Wireless is more or less impossible. We've heard of people trying, but so far no success stories.
If you wish to take a Sprint device to T-Mobile or AT&T, you may be able to do so with LTE-capable devices and Apple iPhones...but there are no guarantees. Some handsets sold by Sprint are marked as 'global' phones, meaning they are also have room for a SIM card despite running on Sprint's CDMA network.
As confusing as it is, if you can get your Sprint phone unlocked, there is a chance you can have it activated for service on a GSM network - but you'll need to speak with your new carrier and ask whether they'll accept the make and model of your handset.
Even if you do get the all-clear, getting your phone unlocked is the tricky part. While Sprint are happy to unlock phones for international use (provided the device is paid off and the customer's account is in good standing), the company isn't as enthusiastic about unlocking devices when customers wish to take them to another carrier. There's more info about the unlocking process - and what a headache it can be - here.
And if you do manage to get your Sprint phone unlocked and find a carrier that agrees to let you bring it on to their network, it's unlikely that the phone will work in quite the same way as it did on Sprint, due to the differences in carrier networks we've discussed above.

support.sprint.com/.../kyocera/duramax/kyocera_dura.

The manual can be found here:
http://support.sprint.com/global/pdf/user_guides/kyocera/duramax/kyocera_duramax_ug.pdf

You may download a copy of the Duramax manual at Sprint com

go to your retailer and ask for a cell phone headset converter which plugs into yr phone and your home surround system. in the back where you see white and red,jacks. this will allow you to hear songs,poeple. over your, home speaker system.one side should hv yellow,white,red,plugs the other a metal insert which goes into yr headset. bring yr phone to the store.

You cannot use a Sprint phone with at&t service even if you get it unlocked, Sprint phones do not use SIM CARD and AT&T uses sim cards for their service.

if you call customer service they can assist you with unlocking the device over the phone or a Service and repair center can unlock it for you

you have to take it to a mobile service ecnter and have them unlock it or call sprint and have them give you the code.