Josmund
The bolt seems to be tight to a point you can't open the action. Is there a lever or switch that must be thrown to open the action or is it just locked up?
Question... will the bolt handle lift up? If it will do that but will not pull back it is the older DISC that uses Orange plastic jackets. There is a black set screw on the left side of the receiver you have to take out to get the bolt out. The stock might also have a prominant Monte Carlo rise and then a drop down to the recoil pad.
It is stainless or blued?
Tools... the same allen wrench that fits the bolt screw will fit the lug screw under the gun. To pull the breech plug, there is a Knight tool, but you can use a 7/16 socket, long extension, and ratchcet - be care not to damage the trigger sear.
To take the bolt apart if it is the older bolt you will need a Knight 'C' or a 7/16" open end wrench can substitute.
If it has open sights on it or the place to put them then it is an Extreme - no sights or place for them then it is an Elite.
This should get you started....