Before you can get the "Let's do Th..." achievement, you need to reach around Level 40 with your character. You should then have enough skill points and money. You need to buy the Shaped Charge skill from the Technician skill tree. It requires eight skill points and costs $712,500. After buying the skill, make sure to select the trip mines in the inventory, and choose the Two-Piece Suit (armor). It will make you run faster. The recommended weapons to use are ones with good mobility, and do not add any modifications. The mods usually make the weapons heavier and slow you down a little bit. Once the Ukrainian job begins, immediately run to the rooms in the back of the jewelry store. Plant an explosive charge on one of the safes. The safe that contains the tiara (mission objective) is random. Take the tiara, and go back to the van as quickly as possible.