1. A Yisrael, but not a Kohen, may give money to another Yisrael as an incentive for the second Yisrael to give his Terumah to a Kohen relative of the first.
2. The Gemara lists many leniencies that apply to Terumah that originates from outside Eretz Yisrael, due to the fact that separating such produce as Terumah is required only mid'Rabanan.
3. Shmuel: Tamei people may touch Terumah from outside Eretz Yisrael.
4. A firstborn animal may be kept for one year. The year is counted from Nisan to Nisan.
5. A firstborn animal brought as a sacrifice (i.e. a Korban Bechor) is eaten for two days and one night.
A BIT MORE
1. Kohanim are supposed to receive Terumah and the other priestly gifts specifically as gifts, and not through monetary deals that direct Terumah to himself or to a fellow Kohen. However, there is nothing wrong with a Yisrael making a monetary arrangement in order to direct someone's gifts to a Kohen who is his relative.
2. Rava: A Kohen may engage in monetary dealings to receive such Terumah from its owner. Shmuel: Such Terumah is nullified in a mixture with a majority of non-Terumah.
3. People who are Tamei for reasons other than a discharge of bodily fluids may eat Terumah from outside Eretz Yisrael.
4. This excludes the possibility that the year for firstborn animals ends at a certain month, such as Tishrei (instead of having a special Rosh Hashanah for firstborn animals).
5. There is a discussion in the Gemara about whether this is derived from the verse, "Shanah b'Shanah," or whether it is derived from a comparison to Shelamim.