Not sure what to do with last year's holy oils?
The Book of Blessings, Chapter 32, Order for the Blessing of a Repository for the Holy Oils, Introduction, paragraph 1127, states:

Each year when the bishop blesses the oils and consecrates the chrism, the pastor should see that the old oils are properly disposed of by burning and that they are replaced by the newly blessed oils.

The guideline for the disposition of sacred items "burn or bury" applies to the disposition of the holy oils. You may consider burning them in the new fire at the Easter Vigil.

It is not fitting that the holy oils be burned along with regular trash or other non-religious refuse.

An alternative to burning is burying the unused oils in a sacred place. One fitting place may be on the church grounds near the church building. This can be accomplished by digging a small hole along the foundation of the church. There is no environmental concern as the oils and chrism essence are non-petroleum based and will eventually be absorbed into the ground.

If the quantity of oil is so large that burying them on the church ground is not feasible, an alternative place to bury the oils is a Catholic cemetery. Your Catholic cemetery director can assist with the disposition of the oils by burying them near a shrine area on the cemetery grounds.

Old holy oil containers or the ambry vessels that might contain any residue are to be cleansed with hot soapy water to dilute the olive oil and essence of chrism. This soapy water should be emptied into the sacrarium or emptied directly into the ground next to the church in a similar manner and location as recommended for burying old oils.