PAYDAY 2

The earliest you can get this is at level 38. This is due to the fact that you need to put 44 skill points into the Enforced skill tree to unlock the ability to wear this and by level 38 you will have exactly 44 skill points.

This should be used if you are just buying these skills to then respec. No thought was put in to what skills I selected there, just the cheapest way

It costs 1,952,500 to unlock this skill "cheaply". Remember that respecing means you lose some of the spent cash so it will be costly unless you have a mass amount of spare cash

Once you have the skill bought, go into armor and put on Improved Combined Tactical Vest.

In Payday 2, the contents of your Inventory and your chosen Skills are saved locally in the "Player progression" file on your 360's hard drive. As such, if you copy the "Player progression" file to another source of memory for your 360, such as a flash drive, and purchase additional weapons or skills, those changes will only synchronize with the specific "Player progression" file from the source of memory that you have selected.

What does this mean? All of the achievements relating to purchasing skills or adding to your inventory can be gained by making local copies of your "Player progression" file on an alternate source of memory than your primary hard drive, and using this copied file to make any desired changes to your selection of inventory and skills, with no resulting change in your primary "Player progression" file.

To unlock the "Man of Iron" achievement, you can still follow Kornfan2007's excellent guide, but now you can respec your skills with a local copy of the "Player progression" file on another source of memory, without having to spend any extra money on your primary "Player progression" file.

Solution for Man of Iron In PAYDAY 2

Credit for this solution goes to GatorFist.