This achievement will pop fairly early in the game; mine was around 50 minutes into play. There is no specific solution for this achievement - simply play through the game and you will have the achievement in short order.
In terms of general advice:
- I finished the game without once using my melee weapon; I killed every single enemy with Van Helsing's ranged weapons;
- Ensure you set your companion to 'melee' mode if you do that - that will make most enemies flock to the companion, leaving you free to pick them off from a distance;
- Pick up every item of loot you can, and make sure you check on your inventory screen whether any of the items can improve your stats;
- Your talents can ease the difficulty of the game: pick some smart talents, such as the one where you can summon two 'allies' to fight beside you, as well as boosting your lightning strike;
- Running away is always an option! Don't get in over your head, if it's a big group and you're not confident you can kill them all, back off and pick them off 2/3 at a time. I died several times due to rushing headfirst into a maelstrom of enemies!