First set the required epoch in the calendar.
Then
L = mean longitude at the epoch
ϖ = longitude of the perihelion
Ω = longitude of the ascending node
i = inclination to the ecliptic plane
e = eccentricity
a = semimajor axis
q = perihelion distance
Q = aphelion distance
n = sidereal mean daily motion
P = sidereal period
p* = mean synodic period
v = mean orbital velocity
The calculation scheme for the elements is that given in Chapter 31 of Jean Meeus "Astronomical Algorithms" (2nd edition).