Thomann Baritone EU Ukulele with PU

I've got my guitar today. By coming in the airport to that worthless UPS, that just storaged my parcel for two days. But alright, it's my problem that just ruined my own day. Uke looks great, i have nothing to criticize in desighn. But, I have only one, i guess the last question to Thomann. How to tune your "baritone" uke? Two top strings without any problems, D and G suitable, alright. But the bottom ones... Those just near to blew up when i'm trying to tune them into H (B3) and E4 respectively. I know that basic strings usually shity ones, but this is even worse than shity. Maybe i'm doing something wrong? Which tuning is basic for this strings? Or it needs some time to become longer, coz now i just scared to tune them :/