If you are looking for the Destiny guide for the The Dark Below on upgrading the weapons and armor through Xur, here is the quick guide for you, according to the report of VG247.

According to the report of VG247, the Destiny guide you should know first is that to upgrade the exotic gear you will need to talk to Xur, the vendor who appears in the towers on weekends. "Xur will upgrade a single Exotic item, increasing its damage or defence cap - and presumably its maximum Light level too."

The first Destiny guide you should learn is that upgrading an exotic item will reset your perks, if you happen to upgrade your exotic with all perks unlocked, the item's stats will be dropped after you upgrade, and increase the previous level until perks will be unlocked.

Furthermore, you can boost your new exotic, so it will not need to unlock the perks before you give it to Xur.

Moreover, another Destiny guide you should remember that the Xur sell the Exotic shards at a price of seven Strange Coins.

Meanwhile, Xur will only upgrade specific Exotic each week, Xur will only offer a "small selection of upgrade options each time they visit the tower."

Have fun playing!