All 6 Uses

however
in
The Death of Ivan Ilych
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He could not, however, be blamed for that, and Ivan Ilych still obeyed his orders implicitly and at first derived some comfort from doing so.†
Chpt 4 *

however = a word used to connect contrasting ideas as when using though, in spite of that, in contrast, nevertheless, etc.
At last, however, he went to his study and did what was necessary, but the consciousness that he had put something aside — an important, intimate matter which he would revert to when his work was done — never left him.†
Chpt 5
But however much he pondered he found no answer.
Chpt 9 *

however = regardless of how
The chief thing however was that he had his official duties.†
Chpt 2
He however knew that do what they would nothing would come of it, only still more agonizing suffering and death.†
Chpt 7
However ...†
Chpt 11

Definitions:

(1) (however as in: However, complications may...)
though (or another expression that connects contrasting ideas)

Based on idea 1 we might not expect idea 2, but this is a way of saying that even though idea 1 exists, we still have idea 2. Synonyms include in spite of that, despite that, nevertheless, nonetheless, on the other hand, in contrast and but.
(2) (however as in: However much she tried...)
to whatever degree (regardless of how much; or whatever unspecified amount)
(3) (however as in: However you do it, get it done!)
in whatever way
(4) (meaning too rare to warrant focus)
Much more rarely (and arguably incorrectly), however can be used to intensify the word how, as when one says "However did you find her?" Grammarians would suggest using two words for that usage: "How ever did you find her?"