Hi, papy,
Probably the easiest start for you would be getting programs from Galaxy 19. The satellite is at 97 W; for St. Louis its true (not magnetic) azimuth is 190.8 degree, and its elevation is 44.7 degree.
Seems your dish has polar mount. Assuming its actuator is disengaged, you could move the dish manually, following the arc with satellites.
Definitely, to use your Ku universal LNBF, you need to place it, like FaTAir said, in the focal spot of this dish.
Therefore you have to remove the old LNA, and install LNBF in its place.
If on May 11 is a sunny day, at 1.13 to 1.14 PM the Sun will be at azimuth close to 191 degree, so, you have to turn the dish as to get the shadow of LNBF exactly below the dish's center, on the vertical axis of the dish.
Your receiver has to be pre-programmed to receive one of Galaxy 19 transponders.
Make sure with an angle finder that the dish is pointing to the elevation (altitude) 44.7
If your LNBF is too close to the dish, it will not get signal "condensed" enough - see the following picture
