Done Need help with these sentences

[stlwright]

留年して2年からこっちに転入してきたらしいぞ (not sure)
He was held back twice and It seems that he entered here his sophomore year.

へえじゃ一コ上?
Eh? So you're one up?

どうもとっつきずれーよな (not sure) どうも=thanks

そのせいかな (not sure)
I wonder if that's the reason

 

[mikkih]

留年して2年からこっちに転入してきたらしいぞ (not sure)
He was held back twice and It seems that he entered here his sophomore year.

へえじゃ一コ上?
Eh? So you're one up?

どうもとっつきずれーよな (not sure) どうも=thanks

そのせいかな (not sure)
I wonder if that's the reason

(1) He was held back twice and It seems that he entered here his sophomore year.
---> get rid of "twice"
Looks like he was held back and ....

(2) Eh? So you're one up?
--->The speaker is still talking to his/her friend about the transfer student.
Ah./I see./Is that right?/Oh, really? So is he/she a year older (than us) then?

(3)
どうも = どうしても just can't
とっつきずれー　＝　とっつきにくい　difficult to approach

(4)
Maybe that's why.