Seats in Row E of Section 300 are located just outside of the section entry tunnel, and are designated as handicap accessible seating as they require no steps to get to the seats from the concourse. Being handicap accessible seats, they are given a unique section names (i.e. 300A, 300W, 300R), however rest assured that they seats you mentioned (Row E Seats 1-4) are all located together in the top row of the lower portion of Section 300.

To reach these seats, you walk through the entry tunnel to Section 300, and they will be located just in front of you (without having to walk up or down), and will be on the right side of the row as you face the field.

Handicap Accessible Seating in Section 300 at CenturyLink Field
Seats in Row E of Section 300 are designated for handicap accessible seating, and can often be classified as either Section 300W, 300R, or 300A