My gearbox light came on. Then turned car off gearbox light is off but no curse control. I think i need gear oil just found out today it takes gear oil. Where do you put the oil. Have had car two year

It is possibly your TCM( tranmission control module) as it gets wet these symtoms comes up, it is lacated under the dash on the passenger side , best solution is to remove it clean the inside of the tcm with electric cleaner spray and then waterproof it so in the future it doesn't get wet. I used ziplock bag and taped it firmly and didnt get this problem since . Your second question about refilling atf , it is best to drain the atf as mmuch possible from the drain plug , which is located near the passenger side diff , its big nut after removing the drain plug you should get out 3.5-4 quarts , refilling atf is quite easy , refill plug is located under the battery housing near the water pump. Best compatible cheap atf for x-type is Castrol multi import , or castrol synthetic atf which complies with Nissan's transmission requirement. Weird enough this car has nissan's tranny.Just to be one the safe side after draining atf fluid put in 4 quarts. Hope this solves your problem , goodluck.