Hi, I was looking for a little advice. I feel I would be able to increase my db chest press but I am struggling to lift the dumbells into position. Currently I am able to use 17.5 kg dbs but can't get the 20 kg dbs into place. I know I could press them because I can press more than 40 kgs using the bar bell on a rack. Is there any specific training I could do to increase my overall upper body strength enough to swing the 20 kg dbs into place? I am suffering from the same problem with the db shoulder press. I am not failing on the press (15 kg/db) but I can't get the 17.5 kg dbs into position.
I would be grateful for any suggestions.

You have 2 choices: a spotter to help you get the weights up or hooks. Most gyms have a pair of hooks somewhere- you may have to ask at the front dest or ask a trainer where they are. Drag a flat or incline bench into a power cage or squat rack and set the bar about 6 inches higher than you can reach when you are on the bench. Set the hooks on the bar. Put the dumbbells in the hooks. They are then in the "up" position for you already.

Do you know how to "kick up" weights? This works for a while, but I've reached the point that I can't kick up enough weight and need an experienced spotter to do chest and shoulders.

Mel

For heavy seated dumbell overhead presses, I do them one arm at a time and use the other hand to get the weight in place and provide a spot. For DB benching I place the weights on my thighs while seated and then lean back onto the bench. Definitely try this first with a light weight.

Getting really strong on hammer curls will help, especially with the "kick up" method Mel described for your OHP.

Some people also do floor presses with heavy dumbells ("Bench pressing" without a bench). Getting the 'bells into position on a floorpress is probably alot less risky than with a full range of motion benchpress.