Soviet diagrams showing areas where to shoot enemy tanks are pretty common. There were both elaborate ones showing various weapons printed at the Publisher of the People's Commissariat of Defense and simpler ones, produced in the field, showing whatever weapons were relevant for the unit that printed them. Here are two such flyers for the Panther.
The first one is relatively well known. Each drawing of a shell shows the range and caliber with which you can destroy a Panther tank. The small bullets are 14.5 mm bullets fired from the PTRD or PTRS. The large tube symbol under that is HE, a projectile partially filled with red is an AP shell, a fully red projectile is solid AP shot. The red arrowhead projectile is 45 mm APCR.
In addition to showing where to shoot with cannons or anti-tank rifles, the diagram tells the reader to fire at vision slits with rifles and machine guns, throw anti-tank grenades at the driver, radio operator, and rear turret hatches, and throw Molotov cocktails onto the engine deck. Additionally, the instructions tell you to shoot the barrel and the commander's cupola with any available weapon. The tracks can be blown off with TMD-B mines.
This instruction manual printed around the same time is for just the 76 mm ZIS-3 gun. It's considerably simpler, but includes a new type of ammunition: 76 mm APCR shown in red. The blue shell is AP and the green one is HE.
From 800 meters, the gunner is instructed to fire AP or APCR at the gun mantlet (specifically at the foundation of the barrel) and AP at the tracks. This matches the first diagram. With a 76 mm gun there isn't much else you're going to do to a Panther from this angle.
From the side you have more options. HE can destroy the tracks and running gear. With either AP or APCR you can penetrate the side of the hull and turret from 800 meters. Interestingly enough, the big diagram gives a distance of 1000 meters for the side of the hull with the 76 mm gun.
From the back, the gunner is once again instructed to shoot from 800 meters. HE can disable the tracks, AP and APCR can also penetrate the rear of the hull or the turret. The range is again more pessimistic than in the big diagram, as that one also gave a figure of 1000 meters for firing at a Panther's rear with a 76 mm gun.
This diagram shows similar information. No ranges are given, but the caption reads "vulnerable parts of the tank for the 76 mm ZIS-3 gun" with circles indicating where to aim. From the front, the gunner's only hope is the base of the gun. From the sides, the best targets are the upper hull, turret, or drive sprocket. From the rear, the best place to aim is the back of the turret and the tracks.